Rocker Arm - 1900cc Waterboxer, 1600cc (CT Engine Code) - 9mm Valve Adjusting Screw

This genuine Volkswagen rocker arm is the correct original-spec replacement for pre-1988 VW Type 25 / T3 buses fitted with 1900cc Waterboxer engines or 1600cc aircooled CT engines. Manufactured by Volkswagen to OE standards, this rocker arm ensures correct valve train geometry, smooth operation, and long-term reliability.

The rocker arm is a critical valvetrain component that transfers motion from the pushrod to the valve stem, converting camshaft movement into precise valve opening and closing. On Waterboxer and CT engines, correct rocker arm specification is essential to maintain proper valve timing, minimise wear, and ensure quiet operation—particularly on engines using hydraulic cam followers.

This version is designed for 9mm valve adjusting screws, as used on the specified early T25/T3 engines. Being a genuine VW part, it offers the correct metallurgy, heat treatment, and contact surface finish, reducing the risk of premature wear to valve tips, pushrods, or rocker shafts often associated with inferior aftermarket alternatives.

Ideal for engine rebuilds, cylinder head work, or replacing worn or damaged rocker arms to restore factory-correct performance.

Fitting & Required Parts

• Quantity: Sold each – 8 required per engine

• Adjusting screw: 025109451 (sold separately)

• Adjusting nut: N0111531 (sold separately)

• Designed specifically for 9mm adjuster screws

• Always inspect rocker shafts and spacers during installation

Engine Compatibility

Suitable for engines with the following codes:

• CT – 1600cc Aircooled

• DG, SP, EY, DF, DH, GW – 1900cc Waterboxer

Applications

• Rocker Arm – Genuine VW

• VW Type 25 / T3 Bus: 1983 – 1988

• Also fitted to:

  • Late Mexican Beetle

  • Brazil Kombi